Railway car dual access level selection apparatus

ABSTRACT

A railway car has a doorway with a pair of oppositely moving doors and a stairwell narrower than the doorway having one side aligned with one side of the doorway and a set of steps descending from the floor of the car to the doorway at a lower level. A platform is supported by a plurality of parallel links pivotable at each end on a pair of bars movable in tracks in the stairwell. The platform includes a cam follower engaging a camtrack in the stairwell to guide movement of the platform between a lower level access position under the floor and an upper level access position covering the stairwell at floor level. A stop biased to normally engage the door on the other side of the doorway and prevent its opening past the other side of the stairwell is pulled out of such engagement by a stop actuation mechanism upon engagement of this mechanism by the platform entering its floor level access position. Numerous additional safety features and interlocks to prevent injury to persons using the railway car are also described.

United States Patent [1 1 Anders et al.

[ Dec.9, 1975 1 1 RAILWAY CAR DUAL ACCESS LEVEL SELECTION APPARATUS [75] Inventors: Robert Anders, Westmont; Daniel H. Kussow, Lisle, both of I11.

[73] Assignee: General Motors Corporation,

Detroit, Mich.

[221 Filed: Feb. 11, 1975 [21] Appl. No.: 549,001

Primary ExaminerJohn J. Love Attorney, Agent, or FirmRobert M. Sigler [5 7 ABSTRACT A railway car has a doorway with a pair of oppositely moving doors and a stairwell narrower than the doorway having one side aligned with one side of the doorway and a set of steps descending from the floor of the car to the doorway at a lower level. A platform is supported by a plurality of parallel links pivotable at each end on a pair of bars movable in tracks in the stairwell. The platform includes a cam follower engaging a camtrack in the stairwell to guide movement of the platform between a lower level access position under the floor and an upper level access position covering the stairwell at floor level. A stop biased to normally engage the door on the other side of the doorway and prevent its opening past the other side of the stairwell is pulled out of such engagement by a stop actuation mechanism upon engagement of this mechanism by the platform entering its floor level access position. Numerous additional safety features and interlocks to prevent injury to persons using the railway car are also described.

3 Claims, 7 Drawing Figures US. Patent Dec. 9 1975 Sheet 1 of 3 lllllllllllllll llllllllllllllll U.s. Patent Dec.91975 I sheetzom 3,924,545

wall Q i? am US. Patent Dec. 9 1975 Sheet 3 of3 3,924,545

RAILWAY CAR DUAL ACCESS LEVEL SELECTION APPARATUS BACKGROUND OF THE INVENTION Many railway passenger cars are used on railroad lines having some passenger stations equipped with loading platforms at the floor level of the car and others with loading platforms at or near ground level. This is particularly true of any car designed for use in both electrified or non-electrified areas, since electrified railroad lines generally provide platform access to the cars while non-electrified lines often provide ground level access.

Railway cars providing a dual level access for passengers are well known in the prior art. A typical such railway car has a stairwell adjacent a doorway for passenger access, a set of fixed steps in the stairwell descending toward the doorway and downward to the lower level and a trap door hinged to the floor which, when down, covers the stairwell to provide floor level access and when swung upward and out of the way, opens up the stairwell for lower level access. The trap doors are swung upward or down in each car as the need arises by railway employees riding in the cars; and are not readily adaptable to an efficient powered system controlled automatically or by one operator from a remote location. Other systems, such as those providing a platform on roller tracks or foldable or collapsing steps, generally involve problems of reliability or economic practicality.

SUMMARY OF THE INVENTION This invention is directed toward a dual level access railway car and particularly toward access level selection apparatus for such a car. The apparatus of this invention includes a platform which, while always maintained in a horizontal position, can be moved between a low level access position underneath the floor of the car and a floor level access position covering the stairwell at floor level. The platform is adapted to be moved by an actuating mechanism including an electrically powered motor so that the selection can be made from a remote location. The apparatus is further adapted for provision with devices to sense the presence of passengers in the stairwell or on the platform and circuits responsive to signals from these sensors to halt operation of the apparatus to avoid injury to these persons. The apparatus may further be adapted to control the amount of door opening depending on the position of the platform.

Further details and advantages of this invention will be apparent in the accompanying drawings and following description of a preferred embodiment.

SUMMARY OF THE DRAWINGS FIG. 1 shows a side elevation view of a portion of a railway car including this invention.

FIG. 2 is a section view along line 2-2 in FIG. 1.

FIG. 3 is a view along line 33 in FIG. 2 and an enlarged view of a portion of FIG. 1.

FIG. 4 is a section view along line 4-4 in FIG. 3.

FIG. 5 is a section view along line 5--5 in FIG. 4.

FIG. 6 is a perspective view of a portion of the apparatus of this invention.

FIG. 7 is a perspective view of a stairwell in the railway car of FIG. 1 adapted for this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a railway car 2 has a side wall 3 with a side door opening 4 therethrough. A pair of doors 5 and 6 are slidable sideways toward each other to close door opening 4 and away from each other to open door opening 4.

Railway car 2 rolls on wheels 8 on a track 9 and has a floor 10, as shown in FIG. 7, above wheels 8 at the level of the bottom of door opening 4, as seen in FIG. 1. Just inside door opening 4, floor 10 is interrupted by a stairwell 11, as shown in FIG. 7, provided with a set of steps 12 descending from floor 10 to a lower level at door opening 4 to provide passenger access to car 2 at track or ground level.

Referring to FIGS. 3, 6 and 7, a pair of horizontal sliding track mechanisms 14 are provided, one in the front wall 15 and one in the rear wall 16 of the stairwell just under floor level. Mechanisms 14 include a horizontal track 17 in the stairwell with an outer end 18 near door opening 4' and an inner end 19 extending under floor 10. Each of mechanisms 14 also includes a bar 21 maintained longitudinally movable with respect to the corresponding track 17 by one or more intermediate support members 22. The construction of such mechanisms 14 is well known in devices such as file cabinets having sliding drawers.

A platform 23 is supported in stairwell 11 by means of a plurality of parallel links 24 pivotably connected to each bar 21 and the side 25 of platform 23 adjecent each bar 21, as shown in FIGS. 2 and 6. Links 24 are all of equal length and maintain platform 23 in a horizontal position parallel to bars 21 and floor 10.

As seen in FIGS. 2 and 7, walls 15 and 16 of stairwell 11 are also provided with camtracks 27, each comprising a long horizontal portion 28 located just below track 17 and a-ishort upward curving portion 29 at the outer end of horizontal portion 28 near door opening 4. Each side 25 of platform 23 is provided with a cam follower 30 which is retained in camtrack 27.

By means of track mechanisms 14, parallel links 24 and camtrack 27, platform 23 is movable between a floor level access position in which it covers stairwell 11 at floor level and a lower level access position in which it is retained under the floor, thus opening stairwell 11. Movement of platform 23 is accomplished by moving bars 21' longitudinally within tracks 17. When platform 23 is in its floor level access position, bars 21 are fully into the stairwell 11 and parallel links 24 are generally vertically aligned as shown in FIGS. 2 and 6. In this position} cam follower 30 is well up into the upward curving portion 29 of camtrack 27. As bars 21 are pulled inward under floor 10, links 24 force platform 23 to follow; however, cam follower 30 first forces platform 23 downward, parallel links 24 maintaining platform 23 horizontal at all times. As bars 21 move under floor 10, they pull platform 23, lowered below floor level by cam follower 30 in camtrack 27, under floor 10 to its low level access position.

Bars 21 are moved by a motor driven link and chain mechanism shown in FIGS. 2, 6 and 7. A chain 32 is contained in a long curved chain guide 33 under floor 10 on each side of stairwell 11. Each chain guide 33 extends from a low point adjacent side wall 3 to a high point just under floor 10 near the top of steps 12. Each chain 32 is free to move longitudinally within its chain 3 guide 33 and is connected at its uppermost link 34 to a projecting end 35 of the adjacent bar 21.

The lowest link 36 of chain 32 is connected through a rigid pivotable link 37 to the outer end 38 of a rotatable lever 40, the other end of which is fixed to a shaft 41 for rotation therewith. Since there are two chains 32 and rigid links 37, there are two levers 40; and shaft 41 spans the distance between them underneath steps 12. As shaft 41 turns in one direction or the other, outer end 38 of each lever 40 is rotated in an arc just inside chain guide 33; and this movement is translated through links 37 and chains 32 to bars 21 to move platform 23 between its floor level and lower level access positions.

An electric motor 42, located beneath steps 12, turns a shaft 43 through a worm gear mechanism 44. A lever 46 is attached to shaft 43 and rotates thereabout. The outer end 47 of lever 46 is connected through an adjustable length link 48 to the outer end 49 of another adjustable link 50, the other end of which is fixed to the shaft 41.

As can be seen in FIG. 2, when platform 23 is in its floor level access position, link 48 passes below the axis of shaft 43 in an over-center arrangement to lock platform 23 in that position. As motor 42 turns shaft 43 and lever 46 clockwise, outer end 49 of lever 50 is first pulled slightly counterclockwise until lever 48 passes the axis of shaft 43. Then lever 50 is rotated clockwise by link 48 and turns shaft 41 and levers 40 clockwise with it. Naturally, to return the mechanism to the floor level access position from the lower level access position, motor 42 turns shaft 43 in the opposite, or counterclockwise direction; but no over-center arrangement is provided in the lower level access position.

Referring to FIGS. 1 and 3, it is apparent that door opening 4 is wider than stairwell 11. Therefore, provision is made for limiting the opening of door 6 when platform 23 is in its low level access position, so that passengers cannot walk off floor beside stairwell 11 and fall to the track 9 or ground.

To accomplish this, a bolt or movable stop 52, shown in FIGS. 4 and 5, is normally biased by a spring 53 through an opening 54 in floor 10 into the underside of door 6. A fixed stop 55 is disposed in door 6 such that it will engage bolt 52 when door 6 has opened as far as wall of stairwell 11 to prevent further opening. The lower end 57 of bolt 52 is slotted, as shown in FIG. 5, and pivotably engaged through a pin 58 with a slotted lever 59 fixed to one end of a shaft 60. Shaft 60 is rotatably disposed in bushings 62 in a bracket 63. At the opposite end of shaft 60 from lever 59 is a trip lever 64 which, when tripped by one of the bars 21 as platform 23 enters its floor level access position, rotates shaft 60 to pull bolt 52 against the bias of spring 53 out of door 6 so that door 6 can open completely. When platform 23 moves out of its floor level access position, bar 21 disengages'from trip lever 64, thus allowing spring 53 to move bolt 52 back into door 6. In addition, a switch, not shown, may be provided which is actuated by shaft 60 or separately tripped by bar 21 to insert additional resistance in the electric power supply circuit for the operating motor, not shown, of door 6 whenever the opening of door 6 is limited by stop 52. This minimizes the stall torque when the limited travel door 6 reaches the stop before the full travel door 5 is opened fully and prevents an electrical overload of the door 6 motor.

The operation of motor 42 to move platform 23 and the operation of additional motors, not shown, to open and close doors 5 and 6 are controlled through electrical switching circuits, not shown, from a remote location. This system is set up so that the platform-is always in its floor level access position when the doors are closed, but an operator can choose to have the platform in the floor or low level access position when the doors open. If the operator chooses the low level access position, the platform moves to this position only when the operator signals for door opening and completes the move before the doors begin to open. Similarly, from the low level access position, the platform moves to its upper level access position upon a door closing signal from the operator and completes this movement before the doors actually begin to close. Platform movement, whenever necessary, occurs at the time of door opening or closing and always precedes it. This may be accomplished with standard limit switches and circuitry.

As an additional safety feature, pressure sensitive pads 66 are provided on steps 12; and pressure sensitive pads 65 are provided on platform 23 and the immediately surrounding area of floor 10. Pads 66 and 65 are a conventional form of electric switch actuated by pressure thereon which can be connected in the electrical control system to prevent actuation of motor 42 when a passenger is standing in a place where his safety might be in danger. Pads 66 are activated upon initiation of movement of platform 23 from its lower level access position to its floor level access position and are adapted to prevent such movement while a passenger is standing on the steps. Pads 65 are activated during the opposite movement of platform 23 and are adapted to prevent such movement while a passenger is standing on platform 23 or the immediate surrounding area of floor 10.

The apparatus of this invention is thus seen to be a practical base on which to design a complete railway car dual level access system in which whatever safeguards or controls are desired are easily added and automatic control is possible. As such it represents an advance in the state of the art of railway car design.

The embodiment of the invention as described above is a preferred embodiment; but equivalents will occur to those skilled in the art. Therefore the scope of this invention should be limited only by the claims which follow.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a railway car having a floor, a sidewall, a doorway through the sidewall, and a stairwell having steps descending from the floor to the doorway at a lower level, access level selection apparatus comprising, in combination:

a platform having a cam follower projecting therefrom; a pair of horizontal parallel platform tracks in the stairwell; a longitudinally movable bar in each platform track; a plurality of parallel links connecting the bars to opposite sides of the platform to support the platform parallel to the floor and move the platform with the bars horizontally between the stairwell and a lower level access position under the floor; the links further being pivotably connected to the bars and the platform, whereby the platform is vertically movable in the stairwell to a floor level access position covering the stairwell and continuous with the floor; and a camtrack in the stairwell engaging the platform cam follower to guide the platform between its floor and lower level access positions with longitudinal movement of the bars.

2. In a railway car having a horizontal floor, a sidewall with a doorway therethrough, and a stairwell having steps descending from the floor to the doorway at a lower level, access level selection apparatus comprising, in combination:

a platform having a cam follower projecting therefrom; a pair of horizontal parallel platform tracks extending from under the floor across the stairwell toward the door; a longitudinally movable bar in each platform track; a plurality of equal-length parallel links connecting the bars to opposite sides of the platform, whereby the platform is supported parallel to the floor and translatable horizontally with the bars between the stairwell and a lower level access position under the floor, the links further being pivotably connected to the bars and the platform, whereby the platform is vertically movable in the stairwell to a floor level access position covering the stairwell at floor level; and a camtrack in the stairwell comprising a long horizontal portion adjacent one of the platform tracks and a short upward curving portion at the end adjacent the door, the cam follower engaging the camtrack to guide the platform with longitudinal bar movement between the floor and lower level access positions.

3. In a railway car having a floor, a sidewall, a doorway through the sidewall, a stairwell narrower than the doorway adjacent thereto and having one side aligned with one side of the doorway, a set of steps in the stairwell descending from the floor to the doorway at a lower level, and a pair of doors in the doorway, the doors being slidable apart sideways to open the doorway and slidable together to close the doorway, access level selection apparatus comprising, in combination: a platform having a cam follower projecting therefrom; a pair of horizontalparallel platform tracks in the stairwell; a bar longitudinally movable in each platform track; a plurality of parallel links connecting the bars to opposite sides of the platform to support the platform parallel to the floor and move the platform with the bars horizontally between the stairwell and a lower level access position under the floor, the links further being pivotably connected to the bars and the platform, whereby the platform is vertically movable in the stairwell to a floor level-access position covering the stairwell at floor level; a camtrack in the stairwell engaging the platform cam follower to guide the platform between its floor and lower level access positions with longitudinal movement of the bars; a stop biased to an engaged position in which it engages the door on the other side of the doorway to limit its opening movement to the other side of the stairwell and having an unengaged position in which it does not so limit the opening movement of the other side door; and a stop disengagement mechanism actuable by the platform entering its floor level position to move the stop to its disengaged position and effective upon movement of the platform from its floor level position to allow the stop to return by its bias to its engaged position. 

1. In a railway car having a floor, a sidewall, a doorway through the sidewall, and a stairwell having steps descending from the floor to the doorway at a lower level, access level selection apparatus comprising, in combination: a platform having a cam follower projecting therefrom; a pair of horizontal parallel platform tracks in the stairwell; a longitudinally movable bar in each platform track; a plurality of parallel links connecting the bars to opposite sides of the platform to support the platform parallel to the floor and move the platform with the bars horizontally between the stairwell and a lower level access position under the floor; the links further being pivotably connected to the bars and the platform, whereby the platform is vertically movable in the stairwell to a floor level access position covering the stairwell and continuous with the floor; and a camtrack in the stairwell engaging the platform cam follower to guide the platform between its floor and lower level access positions with longitudinal movement of the bars.
 2. In a railway car having a horizontal floor, a sidewall with a doorway therethrough, and a stairwell having steps descending from the floor to the doorway at a lower level, access level selection apparatus comprising, in combination: a platform having a cam follower projecting therefrom; a pair of horizontal parallel platform tracks extending from under the floor across the stairwell toward the door; a longitudinally movable bar in each platform track; a plurality of equal-length parallel links connecting the bars to opposite sides of the platform, whereby the platform is supported parallel to the floor and translatable horizontally with the bars between the stairwell and a lower level access position under the floor, the links further being pivotably connected to the bars and the platform, whereby the platform is vertically movable in the stairwell to a floor level access position covering the stairwell at floor level; and a camtrack in the stairwell comprising a long horizontal portion adjacent one of the platform tracks and a short upward curving portion at the end adjacent the door, the cam follower engaging the camtrack to guide the platform with longitudinal bar movement between the floor and lower level access positions.
 3. In a railway car having a floor, a sidewall, a doorway through the sidewall, a stairwell narrower than the doorway adjacent thereto and having one side aligned with one side of the doorway, a set of steps in the stairwell descending from the floor to the doorway at a lower level, and a pair of doors in the doorway, the doors being slidable apart sideways to open the doorway and slidable together to close the doorway, access level selection apparatus comprising, in combination: a platform having a cam follower projecting therefrom; a pair of horizontal parallel platform tracks in the stairwell; a bar longitudinally movable in each platform track; a plurality of parallel links connecting the bars to opposite sides of the platform to support the platform parallel to the floor and move the platform with the bars horizontally between the stairwell and a lower level access position under the floor, the links further being pivotably connected to the bars and the platform, whereby the platform is vertically movable in the stairwell to a floor level access position covering the stairwell at floor level; a camtrack in the stairwell engaging the platform cam follower to guide the platform between its floor and lower level access positions with longitudinal movement of the bars; a stop biased to an engaged position in which it engages the door on the other side of the doorway to limit its opening movement to the other side of the stairwell and having an unengaged position in which it does not so limit the opening movement of the other side door; and a stop disengagement mechanism actuable by the platform entering its floor level position to move the stop to its disengaged position and effective upon movement of the platform from its floor level position to allow the stop to return by its bias to its engaged position. 